Method and apparatus for equalizing the tension in a plurality of strands



April 11, 1944. w BU 2,346,358

METHOD AND APPARATUS F IZING THE TENSION IN A PLURA TRANDS SSE OR EQUAL LITY OF S Filed Nov. 24, 1942 [Janeen 1 512552 Patented Apr. 11, 1944 as assa Arnrice METHOD AND APPARATUS" FOR EQUALIZ- we ran rnnsronms r aAu'rY or STRANDS Warren F. Busse, Akron, ours, assignor to The .B. F; Goodrich Compan corporation of New York y, New York, N;. Y; a

' Application November- 24, iota-semi stereo" Claims. or. 5'i'-=-1 06) This invention relates to a method and apparatus for equalizing the tension on a plurality of strands and particularly. to a device for main taming an equal tension on each of a plurality of threads, yarns, or plied'yarns of a textile materlal prior: to their twisting into plied yarns or.

cards.

In the construction of plied-yarns or cabled yarns, such as in the manufacture of tire cord,

for example, by twisting together'a plurality of single yarns or plied yams-by means of a conventional twisting mechanism, it is common practice to feed the yarns to-be twisted'directly from bobbins mountedabovethe twister to the feed rolls of the twister. .In such practice, however,

it frequently happens, that the supply bobbins drag unequally ontheir spindles with the result that the yarns supplied to the feedrolls of the twister vary considerably in tension and unequal lengthsof the several yarns are twisted together into a single pliedyarn or cord. The plied yarns or cords thus,obtained obviously d'onot possess,

their maximum strength since the individual I strands share unequally-in resistance to tensile rupture and, under test, a sequential failure of- ,one strand after another occurs at much lower material, cotton or rayon for example, are led from bobbins supported above the feed rolls of a conventional twisting mechanism downward to the rolls through two spaced-apart restricted zones by-mean'sof guide rings or the like ands. friction device interspaced between the two zones.

This friction device comprises a floating trio- .tion member by which is meant a member hav- .ing asubstantia'l degree of freedom in its lateral movement, which engages a bight of each of the strands preferably at equidistant points about its periphery and by frictional drag imparts tension thereto. Since the floating friction I member is movable laterally to the direction of travel of the strands, if any'of the strands unwound from the bobbins possesses a tension greater"than other strands the floating member is forced against the other looser strands taking up the slack and also increasing the tension on these strands by makingthern drag-over a larger. arc of contact. At the same time the tension on the tightstrands is reduced by providing a sho.t-

v er path and reduced friction; As a result the loads than those. required when all plies share ply breaks.

the load equally. 'These are commonly called- Itis accordingly an object of this invention tov provide an eflicient and economical method and apparatus for equalizing the tension on the several yarns supplied from the bobbins priorito their beingfed to the twister rolls so that uniform plied yarns and cords of maximum tensile strength and resistance. to rupture may be obtained. A more general object of the invention is to provide method and apparatus forv equalizing the tension in each of. a plurality of strands regardless of the nature of such strands or the subsequent use various strands are fed to the twister under substantiallyequal tension. g

In order further to explain the invention, reference had to the accompanying "drawing wherein Fig; I illustrating a preferred embodiment of the inventionand.

Fig. 2 is an elevation partly in cross-section taken on the line 2-2 in Fig. 1..

lll'of textile material are "Referring to the drawing, a plurality of strands unwound from bobbins ll and directed in substantially parallel relation through guide ring strands, in pass downward and engage rounded to be made'of the strands. Further objects will appear. hereinafter.

These objects are accomplished in this invention by providing in the-path of a plurality of strands having varying individualtension conditions a single tension equalizing device .which frictionally engages a bight of each of. the strands and is movable radially to the strands in response to increased tension in any of the strands thereby taking up the slack as well as introducing 'agreater frictional drag on the looser strands than on the tighter strands and thus equalizing the tension in all the strands.

In a preferred form of the invention a plurality of strands usually three in number, of a textile grooves in a floating'friction member i3, resting on support I and consisting, as shown, of a'disc but which may partake of any variety of sizes,

shapes or weights, at equidistant points about the periphery of the floating member. The

strands Ill-are spread apart by the friction mem ber l3 and are maintained at the equidistant points by any suitable means such as the rounded as they are unwound from the bobbins II are under unequal tensions the strand under the greatest tension.v will force the floating friction 1 is a perspective view of an apparatus l2. From guide ring l2 the floating member is and its support id to a vertical aperture 16 in same time the tension on the tight strands is Y relieved until a condition of equilibrium is attained and the tension on each of the strands in the span between the support It and the fee rolls I! is substantially equal.

It is well known that the frictional drag on a rope or belt slipping over a pulley is given by the equation f=f e where f and f0 are the ten sions on the two sides of the pulley, k is the co efllcient of friction and 0 is the angle of contact. In this invention the movable floating friction member automatically increases 0 for loose strands thus increasing the drag and the tension, and it decreases 0 for tight strands, thus decreasing their tension.

While the invention may be applied to a pin rality of strands regardless of whether the strands are to be twisted, wound or otherwise used after their tension is equalized, it is par-s ticularly suitable ior equalizing the tension in three plied yarns or a textile material in connection with a twisting device for twisting the three plied yarns into a cord such as a tire cord. For example, it has been found that the ply lil breaks occurring in cotton tire cords twisted from plied yarns has been reduced, by equalizing the tension of the plies prior to twisting in the manner described, from over 75% to less than 10% in a standard test.

it is to be understood that the embodiment of the invention shown and specifically described is merely illustrative of the invention and it is not intended that the invention be limited thereto for numerous modifications and variations which will be obvious to one skilled in the art may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. Apparatus for equalizing the tension in a plurality of strands being advanced together in a generally vertical direction under varying individual tension conditions, said apparatus coin prising means for guiding the strands together through two restricted zones at spaced apart points along a generally vertical path of travel, and a floating friction member spreading the strands apart between the said two zones and engaging a blght of each strand for frictionally tensioning the same, the said member being controlled in its location by engagement of the bights of the strands and movable laterally or the direction of the strands by reason of the difference of tension in the individual strands, whereby to increase the frictional drag on the strand having the least tension and to equalize the tension in all the individual strands.

2. Apparatus for maintaining an equalized tension in each of a plurality of strands being advanced together in a generally vertical direction under varying'individual tension conditions said apparatus comprising means for guiding the strands in a substantially parallel relation through two restricted zones at spaced-apart points along a and means for tween the said two zones,

spreading the strands apart be said means comprising actuate a floating friction member having substantial. weight and enga ing the individual strands at equidistant points about its periphery, the said floating member being movable laterally of the direction of travel of the strands by reason of the difference of tension in the strands, thereby increasing the tension on the strands having the least tension and equalizing the tension in all the individual strands.

3. Apparatus for maintaining an equalized tension in each of three strands having varying individual tension conditions, said apparatus comprising guide means for directing each of the strands toward a single frictioning member, a single frictloning memmr resting on. a horizontal support of relatively larger horizontal surface, and engaging a bight of each of the strands at equidistant points about its periphery, and guide means for radially directing each of the strands between and in contact with the surfaces of the frictioning member and the support, the said frictioning member being movable radially to the strands and laterally to the support in response to increased tension in any of the strands thereby increasing the resistances to travel in the other strands by reason of an increase in the radial length of the other strands in contact with the surfaces of the frictlonlns member and the support and equalizing the tension in all the strands.

4. Apparatus for maintaining an equalized tension in each of three strands being advanced together in a generally vertical direction under varying individual tension conditions, said ap paratus comprising upper and lower guides for guiding the strands in a substantially parallel relation through two restricted zones at spacedapart points along a generally vertical path of travel, said lower guide comprising a horizontal support having a vertical aperture therethrough, and means located between said gm'des for spreading the strands apart and imparting increased tension thereto, said means comprising a floating disc having substantial weight resting on said horizontal support and centered above the said aperture therethrough, said disc engaging a bight of each of the strands at equidistant points about its periphery and effecting a-radial course in each of the strands as they pass from said points to said aperture, the said disc being displaceable laterally along said support in re- .sponse to inward pulls resulting from relatively generally vertical path of travel,

increased tension in any of the strands and being adapted to force the other strands outward increasing their tension as such lateral displacement occurs whereby to equalize the tension in each of the three strands.

5. A method for equalizing the tension in a plurality of strands being advanced together in a generally vertical direction under varying individual tension conditions which comprises directing the strands together through two restricted zones at spaced-apart points along a generally vertical path of travel, spreading the strands apart between the said two zones by means of a floating friction member engaging each of the strands at equidistant points about its periphery, the said floating friction member being movable laterally of the direction of travel in the strands by reason of the difference of tension in the strands, and imparting tensionto the individual strands by frictional engagement with said floating member inversely proportional to the original tautness of the individual strands.

WARREN F. BUSSE. 

